Added system to build LegacyCamera if specified

Must be built with the LegacyCamera commit that moves PanoramaActivity
to the root directory.
Inspired by a patch by Bryan Gantt <dragonzkiller@gmail.com>
Cleaned up and enhanced by Rashed Abdel-Tawab <rashedabdeltawab@gmail.com>

Patch set 1: Initial Commit
Patch set 2: Fix errors with libjni_legacymosaic.so not building
Patch set 3: Clean-up the code

Change-Id: Id59e72ada6893c6f6de2b2f486a637509a50d71d